1. Field of the Invention
This invention relates to data files created using computing applications, more particularly to a file format for use with distributed computing applications.
2. Background of the Invention
Many specific computer tasks may be performed using different software applications. For example, creating a text document may be done on a personal computer (PC) using Wordpad or Word, products of Microsoft Corporation, or Pagemaker a product of Adobe Corporation, as well as many others. Several users may want to share a document, yet not all the users may have the same applications available to them and therefore cannot access the document to be shared.
One solution to this problem is common interchange formats, such as metafiles or rich text files that can be imported to other applications. Similarly, several word processing applications provide the ability to open a file under the File menu as xe2x80x9cOpen As . . . xe2x80x9d where the user can identify the format and the application can then recognize the format and convert it to the application format.
However, neither of these approaches are problem free. In some instances, even if the application recognizes the document format it cannot access the document. In others, some formatting or special features are lost upon conversion. Additionally, the conversion process places an additional burden on the creator of the document, who must take into account the applications available to the other uses.
Some operating systems such as Macintosh(copyright) and Windows(and have association tables that identify the application to be used to open a particular document. In the Macintosh(copyright) operating system a file is tagged with a token and the table associates the tokens with the applications. In the Windows(copyright) operating system the association table correlates the file extension to applications. Unfortunately, neither of these solve a problem that arises with different versions of an application.
For example, the creating user uses an application version 4.0 that has added feature that were not available in version 3.0. Another user wants to view the document, but the file association table for that user opens the document with version 3.0. The viewing user can no longer view anything in the document that needs the added features of version 4.0.
These problems will become more prevalent with the advent of application service providers (ASPs). An application service provider provides subscribers with access to applications such as word processing, multimedia presentation software, accounting and spreadsheet software, etc., across some connection. Subscribers can then use the applications to create documents without having to have the entire application loaded on their PC. This will allow subscribers to have access to a wider number of applications that they may not otherwise have purchased or cannot afford. The higher number of available applications for creating documents will increase the likelihood that other users may not have the correct application on their PC to view the document.
Current solutions to these problems fall into two general categories, embedding applications into the files or embedding information about the applications into the files. The first approach can be seen by U.S. Pat. Nos. 5,835,914, issued Nov. 10, 1998; 5,838,906, issued Nov. 17, 1998; 5,890,172, issued Mar. 30, 1999; or 5,909,684, issued Jun. 1, 1999. The second approach can be seen in U.S. Pat. Nos. 5,761,499, issued Jun. 2, 1998; 5,893,122, issued Apr. 6, 1999; 5,905,991, issued May 18, 1999; or 5,913,210, issued Jun. 15, 1999. However, none of these solutions allow users to not only identify the creating applications, but allow the user to download the application as needed for accessing the file.
Therefore, a need exists for a method of identifying the application used to create a document to allow other users to access the document with the correct application.
One aspect of the invention is a method for creating and opening data files with embedded association information. The method operates within a control application. The control application could be one application with different capabilities dependent upon the characteristics of the user. The control application offers the option of creating or opening a data file. To create a data file, the control application allows the user to select one creating application from a number available on an application server. After the data file is created, the control application embeds association information about the creating application into the data file, including the version of the creating application and a location from where that application can be accessed. To open a data file, the control application examines the association information and determines if the creating application is available. If it is not, the control application uses the location information to access the proper version of the correct application, initializes it and allows it to open the contents of the data file.